计及间歇性新能源的弹性城市电网输配电协同供电恢复方法

Coordinated Power Supply Restoration Method of Resilient Urban Transmission and Distribution Networks Considering Intermittent New Energy

极端灾害频发,给大规模接入新能源的城市电网运行带来巨大挑战。为此,提出一种计及间歇性新能源的城市电网输配电协同供电恢复方法,以提升规模化接入新能源的城市电网系统弹性。针对新能源不确定性建模,提出了一种基于高斯Copula的新能源离线概率建模和实时更新方法,通过实时更新场景预测刻画其出力时变不确定性。基于预测场景,建立了一个计及负荷转供的城市电网双层供电恢复模型。该模型考虑主动的输电系统−配电系统协同优化,通过调整负荷分布、网络重构以及应急资源实时调度进行供电恢复,最小化系统失电量。所提双层供电恢复模型在上层优化各区域高压配网与输电系统运行边界,在下层求解各区域高压配网的重构及应急资源实时调度方案,通过检验输电网交流潮流判断计算过程是否结束。由仿真结果可知所提城市电网输配协同供电恢复方法可有效提升系统弹性,在极端灾害下可保证输电网线路潮流不越限并有效降低系统切负荷量。

Frequent extreme disasters bring great challenges to the operation of urban power grids with large-scale access to new energy.Therefore,this paper proposes a double-layer coordinated power supply restoration model for urban power grids in which intermittent new energy is considered to improve system resilience.Firstly,a method of offline probabilistic modeling and online updating of new energy is proposed,which depicts the time-varying uncertainty of its output via rolling update scenario prediction.Secondly,based on the forecast scenario,a double-layer power supply restoration model of the urban power grid is established considering load transfer.The model considers the active transmission system-distribution system collaborative optimization,and is carried out by adjusting load distribution,network reconfiguration and real-time scheduling of emergency resources.Power supply is restored to minimize system power loss.In the upper layer,the proposed two-layer power supply restoration model optimizes the operating boundary of the high-voltage distribution network and transmission system in each region.In the lower layer,the reconfiguration of the high-voltage distribution network in each region and the real-time scheduling scheme of emergency resources are obtained.Whether the calculation process is over can be judged by checking the AC power flow of the transmission network.The simulation results show that the proposed power supply restoration method can effectively improve the system resilience,ensure that the power flow of the transmission grid line does not exceed the limit,and effectively reduce the load cutting under extreme disasters.